title: cDNA cloning and mRNA expression of retinoid-X-receptor in the ovary of the shrimp Metapenaeus ensis.
abstract: Retinoid-X-receptor (RXR) plays an essential role in the molting process of decapod crustaceans, by forming a heterodimeric complex with the ecdysteroid receptor. However, its role during female reproduction, especially in the process of ovarian maturation, has not been characterized. To get an insight into the molecular events governing the process of ovarian maturation in shrimps, the full-length cDNA of RXR from Metapenaeus ensis was cloned by extension of truncated cDNA by using the RACE technique. The open reading frame of MeRXR encodes a 410 amino acid protein with a deduced molecular weight of 44.8 kDa, and putative pI of 6.64, which roughly matched our observation from 2DE gel. Phylogenetic analysis showed that MeRXR has high similarity to RXR of Penaeus chinensis and P. japonicus. RT-PCR revealed that MeRXR was universally expressed in all tissues investigated. The variation in MeRXR mRNA expression pattern during ovarian maturation was further analyzed by real-time PCR. In contrast to the decrease in MeRXR at protein level with ovarian maturation, MeRXR mRNA level was low in pre-vitellogenic and mid-vitellogenic ovaries, and increased significantly from mid-vitellogenic to late-vitellogenic stages. This result suggests that MeRXR transcripts in the mature ovary probably act as maternal messages for regulating early molting events during embryonic development.
authors.affiliation: Simon F. S. Li Marine Science Laboratory, School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China.
authors.forename: Ju
authors.initials: J
authors.lastname: Cui
authors.forename: Longtao
authors.initials: L
authors.lastname: Wu
authors.forename: Siu-Ming
authors.initials: SM
authors.lastname: Chan
authors.forename: Ka Hou
authors.initials: KH
authors.lastname: Chu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005260:Female; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000187:drug effects; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics; D010053:Ovary / Q000187:drug effects / Q000378:metabolism*; D033561:Penaeidae / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D047488:Retinoid X Receptors / Q000235:genetics* / Q000378:metabolism; D012176:Retinoids / Q000494:pharmacology; D016415:Sequence Alignment; D059467:Transcriptome
chemical_list: D018076:DNA, Complementary; D047488:Retinoid X Receptors; D012176:Retinoids